Things were looking pretty bleak here in Tarrytown, New York, back in January. Stores were closing left and right, people were losing their homes, nobody could find work, and out in the street it was colder than a penguin's flippers. Truly, this was the winter of our discontent. And then Keanu came to town.

Keanu Reeves, the first male movie star I ever interviewed, was in town to make a comedy called Henry's Crime, which he both produced and starred in. It was shot in a funky 19th-century music hall that sits right in back of my office building. The music hall has been used in films as varied as The Good Shepherd, The Preacher's Wife and The Purple Rose of Cairo, partly because it is photogenic and partly because it lies within a 25-mile radius of New York City, so film producers don't have to pay the crew extra travelling expenses. The shoot lasted three weeks: three weeks of sheer bliss for residents of the community. Before Keanu, all was darkness. After Keanu, all was light.

Oh yes, Keanu's visit was a phenomenally uplifting event, primarily because he made himself so very, very available. He was in the grocery store, the convenience store, the delicatessen, always more than happy to sign an autograph or have his picture taken with some prodigiously unattractive local. He was in the post office, standing in line just like everybody else, as if he were not in fact the luminous star of The Matrix, Point Break, Speed, My Own Private Idaho visiting a pleasant but non-luminous suburb. Here was a certifiable immortal, a star of stage and screen, a legend in his own time and a rather good-looking one, yet for the three weeks he was here, he walked among us, breaking bread with the common man, sipping coffee with the hoi polloi, lifting our spirits. He also spent about $170,000 on the shoot. He made people so happy that, for a while there, I was worried that on the day he left they might have to close the Tappan Zee Bridge, to prevent crestfallen locals from jumping into that river. He made that much of an impression.

Keanu's visit to Tarrytown, and the public's reaction to that visit, drives home an important point. Movie stars are the closest thing Americans have to royalty. Even if, as in the case of Keanu Reeves, the royals have drifted down from Canada. Movie stars are objects of veneration, admiration and envy, creatures that inhabit some amorphous netherworld that is anchored in reality, but is not quite in it. It is a world that the rest of us may glimpse, but can never really be a part of. This is primarily because we are not especially good-looking, short on talent, and in any case, lacking in connections.

Movie stars, like authentic royals, understand their role in society. They bring sunshine into our lives, however briefly, and in return we bring money into their lives. Lots and lots and lots of money. Mostly, they bring sunshine into our lives through their efforts on screen, but sometimes, as in the case of Keanu Reeves, they physically make the clouds go away. They are a vital part of daily life in America, and everybody knows it. When they appear on the carpet at the Oscars, it is as if Hera, Zeus and Athena have wafted down from Mount Olympus.

Veneration of movie stars, in theory, flies in the face of America's tenaciously held beliefs about itself. Americans reflexively spit on their politicians, despise their captains of industry, deride athletes as spoiled prima donnas who wouldn't make it through the first day on the assembly line, ridicule religious leaders and sneer at intellectuals. They also have a hard time taking rock stars seriously, especially when they open their mouths about politics. Even when a political figure approaches divine status, as Barack Obama did in 2008, this aura of beatification quickly vaporises, because politicians are hired to solve problems, and once it becomes apparent that they can't solve the problems – at least not overnight – nobody cares how cool they are.

Americans, routinely making a fetish out of the democratic impulse, will go out of their way to show that they are quiet loners and mavericks, brash heirs to the mob who threw all that British tea into Boston harbour back in 1775. They insist that they will not kowtow to Washington, Wall Street or the media. They will not cave in to Big Brother. They will not lay down for The Man. But as soon as a movie star enters the room, they go all weak in the knees and start gushing like schoolchildren.

This may be because deep down inside, Americans know the score. The average American, no matter how dumb, no matter how ugly, no matter how bereft of charisma, truly believes that if things had broken right, he too could have been Chairman of the Joint Chiefs of Staff, or the Most Valuable Player in the Superbowl, or Muhammad Ali, or maybe even Paul McCartney. But not for a minute does he ever beguile himself into thinking that he could be Brad Pitt or Johnny Depp. Much less Angelina Jolie. As Clint Eastwood once expressed it: "A man's gotta know his limitations." Women, too.

Movie stars in this sense have an unfair advantage over politicians and athletes and rock stars. They can age gracefully, they are not expected to do any of society's heavy lifting, and they are almost always placed in situations that they can control, situations that position them in the most attractive light. They are exactly like Britain's royals. They exist to have their pictures taken. They are meant to be seen and not heard. They are entirely ornamental. (This is something Prince Charles may not fully understand.)

People sometimes say that the Kennedy family are royalty, but that is not true. Literally half the country – the Republicans – despise the Kennedys and all that they stand for. And when I say despise, I mean despise. Some people may wish the royals would go away. But by and large people don't hate them. This is not true of the Kennedys. To this day, when rightwingers assemble, their cars are adorned with bumper stickers reminding people that Ted Kennedy once allowed a young woman to drown at the bottom of a lake in Chappaquiddick, Massachusetts. That would never happen to Russell Crowe, no matter how many hotel desk clerks he punched out.

Movie stars enjoy another huge advantage over luminaries in other fields. Political figures, no matter what their original appeal, eventually go out of fashion. They fail to bring their promises to fruition. They lie. They compromise their principles. They become depressing reminders of unfulfilled dreams, promises that were not kept. And then they are forgotten.

Movie stars, by contrast, have an appeal that stretches across party lines, ethnic lines, religious lines, racial lines. This is partly because they are so very glamorous, but also because the very work they do keeps them above the fray. The public has almost nothing but good feelings about movie stars, because they connect us with a time and a place when we were happy. Americans are always happy on Oscar night; even if this year's movies were nothing special, last year's movies were great. The scene toward the end of the Oscars when the gigantic photographs of recently deceased movie stars appear on the television screen is almost biblical in proportion. Like the royals, movie stars exist in a kind of fairyland that they occasionally allow the public to peer into, without actually visiting. Like the royals, you cannot stop being a star once you are a movie star. The light from your star may be subdued or eclipsed but it can never be fully extinguished. Just look at Mickey Rourke.

Like the royals, movie stars lead lives the rest of cannot imagine leading. They are rich, glamorous, powerful, inhabit fantastic homes and do not have to worry about their mortgages or getting their kids into the best schools. They have very nice cars, great clothes, fabulous teeth. Like the royals, they elicit an oddly craven reaction from ordinary mortals. Perhaps this is because the average person knows that he has no chance at achieving immortality so he'd better enjoy the company of the immortals while they're there. Because celluloid heroes never feel any pain. And celluloid heroes never really die.